ARM: 5919/1: ARM: L2 : Errata 588369: Clean & Invalidate do not invalidate clean...

This patch implements the work-around for the errata 588369.The secure
API is used to alter L2 debug register because of trust-zone.

This version updated with comments from Russell and Catalin and
generated against 2.6.33-rc6 mainline kernel. Detail
comments can be found:
http://www.spinics.net/lists/linux-omap/msg23431.html

Signed-off-by: Woodruff Richard <r-woodruff2@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 762ae53..0f1ad74 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -924,6 +924,19 @@ config ARM_ERRATA_460075
          ACTLR register. Note that setting specific bits in the ACTLR register
          may not be available in non-secure mode.
 
+config PL310_ERRATA_588369
+       bool "Clean & Invalidate maintenance operations do not invalidate clean lines"
+       depends on CACHE_L2X0 && ARCH_OMAP4
+       help
+          The PL310 L2 cache controller implements three types of Clean &
+          Invalidate maintenance operations: by Physical Address
+          (offset 0x7F0), by Index/Way (0x7F8) and by Way (0x7FC).
+          They are architecturally defined to behave as the execution of a
+          clean operation followed immediately by an invalidate operation,
+          both performing to the same memory location. This functionality
+          is not correctly implemented in PL310 as clean lines are not
+          invalidated as a result of these operations. Note that this errata
+          uses Texas Instrument's secure monitor api.
 endmenu
 
 source "arch/arm/common/Kconfig"

diff --git a/arch/arm/mm/cache-l2x0.c b/arch/arm/mm/cache-l2x0.c
index 1a14d18..0733463 100644 (file)
--- a/arch/arm/mm/cache-l2x0.c
+++ b/arch/arm/mm/cache-l2x0.c
@@ -56,12 +56,42 @@ static inline void l2x0_inv_line(unsigned long addr)
        writel(addr, base + L2X0_INV_LINE_PA);
 }
 
+#ifdef CONFIG_PL310_ERRATA_588369
+static void debug_writel(unsigned long val)
+{
+       extern void omap_smc1(u32 fn, u32 arg);
+
+       /*
+        * Texas Instrument secure monitor api to modify the
+        * PL310 Debug Control Register.
+        */
+       omap_smc1(0x100, val);
+}
+
+static inline void l2x0_flush_line(unsigned long addr)
+{
+       void __iomem *base = l2x0_base;
+
+       /* Clean by PA followed by Invalidate by PA */
+       cache_wait(base + L2X0_CLEAN_LINE_PA, 1);
+       writel(addr, base + L2X0_CLEAN_LINE_PA);
+       cache_wait(base + L2X0_INV_LINE_PA, 1);
+       writel(addr, base + L2X0_INV_LINE_PA);
+}
+#else
+
+/* Optimised out for non-errata case */
+static inline void debug_writel(unsigned long val)
+{
+}
+
 static inline void l2x0_flush_line(unsigned long addr)
 {
        void __iomem *base = l2x0_base;
        cache_wait(base + L2X0_CLEAN_INV_LINE_PA, 1);
        writel(addr, base + L2X0_CLEAN_INV_LINE_PA);
 }
+#endif
 
 static inline void l2x0_inv_all(void)
 {
@@ -83,13 +113,17 @@ static void l2x0_inv_range(unsigned long start, unsigned long end)
        spin_lock_irqsave(&l2x0_lock, flags);
        if (start & (CACHE_LINE_SIZE - 1)) {
                start &= ~(CACHE_LINE_SIZE - 1);
+               debug_writel(0x03);
                l2x0_flush_line(start);
+               debug_writel(0x00);
                start += CACHE_LINE_SIZE;
        }
 
        if (end & (CACHE_LINE_SIZE - 1)) {
                end &= ~(CACHE_LINE_SIZE - 1);
+               debug_writel(0x03);
                l2x0_flush_line(end);
+               debug_writel(0x00);
        }
 
        while (start < end) {
@@ -145,10 +179,12 @@ static void l2x0_flush_range(unsigned long start, unsigned long end)
        while (start < end) {
                unsigned long blk_end = start + min(end - start, 4096UL);
 
+               debug_writel(0x03);
                while (start < blk_end) {
                        l2x0_flush_line(start);
                        start += CACHE_LINE_SIZE;
                }
+               debug_writel(0x00);
 
                if (blk_end < end) {
                        spin_unlock_irqrestore(&l2x0_lock, flags);